The present invention relates to an assembly of a brake shoe with an associated brake shoe spring.
There are already known brake shoe assemblies in which the brake shoe includes a carrier plate and a lining of friction material secured to the carrier plate, and in which the brake-shoe spring has two legs that merge with and are interconnected by a loop-shaped portion which is received in a recess of the carrier plate and is secured in the recess normal to the plane of the carrier plate.
Furthermore, a brake shoe assembly is known from the German published patent application No. 29 37 149, wherein the brake shoe spring is constructed as a wire spring and its loop-shaped portion is retained in the recess of the carrier plate against movement radially and simultaneously in the circumferential direction of the brake shoe. While there is also a limited axial securing in position of the brake-shoe spring in the direction normal to the opening of the recess prior to the mounting of the brake-shoe spring on a brake caliper, due to the frictional engagement between the brake-shoe spring and the carrier plate since the loop-shaped portion is clamped in the recess of the carrier plate with radial preload, this frictional engagement is discontinued after the mounting of the brake shoe assembly on a brake caliper owing to the decrease in the outer diameter of the loop-shaped portion resulting from the loading of the brake-shoe spring. The clearance between the brake-shoe spring and the recess which results from this diameter reduction is conducive to slipping of the spring out of the recess. This situation is further aggravated by the effect of vibrations on the brake during the operation of the vehicle equipped with such a brake in that such vibrations can actually cause the loop-shaped portion of the spring to slip out of the recess. However, other forces acting on the brake, the brake shoes or the spring, may have the same effect. Of course, this is very disadvantageous since the disassociation of the spring from the brake shoe may result in a loss of the spring and will certainly impair the operation of the brake, if not render the same inoperative.